Conventional warheads of anti-ballistic missiles, especially of the larger size, comprise separate munitions which are positioned in a canister of plastic, composite, aluminum or steel, which is itself contained within the missile skin and structure. These warheads are usually cylindrical in shape and have pre-formed projectiles surrounding a cylinder of explosive. The missile structures themselves are highly specialized, with a heat shield secured to the outer surface thereof. Normally, the warhead is designed as an independent package to be inserted into a missile structure as a component thereof. Pre-formed projectiles, usually in the form of cubes, are placed over the explosive charge and held in place by an exterior layer of fiberglass, plastic, composite, or metal. The entire warhead unit is fitted with a flange and a forward support so that it can be bolted into the missile structure. The warhead structural elements must be rigid and strong to withstand the missile acceleration loads without greatly deflecting or fracturing the explosive or displacing the projectile pattern. These loads are generally supported at the forward and aft flanges where the warhead assembly interfaces with the missile structure. It is usual practice to avoid rings or frames and discontinuities on the missile structure which must be pierced by the warhead fragments.
The missile structure actually duplicates, to a degree, the function of the warhead structure, and also provides stiffness to the sections of the missile forward and aft of the warhead. The warhead is usually emplaced as far forward as possible in the missile because the warhead is the single heaviest and densest component of the missile assembly and, its forward location reduces the amount of ballast that is required for stability and balance. Special effort is always made to position the warhead as close as possible to the outer skin line so as to more fully utilize the internal volume of the missile.
When the warhead is detonated, the projectile pattern must penetrate the missile structure and the missile heat shield to reach the target. This tends to scatter the projectiles, and the precise pattern is perturbed as projectiles are deflected by bits and pieces of structure. In addition, some energy is lost in the penetration and acceleration of the structure by the projectiles and explosive. Because there are really three layers of structure to be accelerated by the explosive, and two to be penetrated by the projectiles, the pattern disturbance and loss of effective charge-to-mass ratio. becomes significant. Furthermore, it is possible for projectile breakup to occur as a result of the skin penetration process, particularly for projectiles with a significant L/D (length to diameter ratio).
Missile and warhead designers have attempted to minimize the losses and disturbances by various techniques including making the warhead casing an integral part of the missile skin and structure. While such procedure eliminates weight, simplifies assembly, and allows the maximum effectiveness within the overall missile diameter constraint for tactical missiles, the requirement for heat shielding limits the general applicability of such an approach, where strategic interceptor missiles are concerned.
Warheads of the prior art have involved the use of a cylindrical projectile casing over a cylindrical explosive container. This necessarily does not utilize maximum volume available and results in an unfavorable aft center of gravity location. The warhead of the present invention is shorter for the same weight, and fits further forward because of its conical shape. This reduces the length of the missile as well as the ballast weight. Furthermore, for the same size, the missile structure weight is eliminated, and with no skin to pierce, less explosive is required and dispersion is eliminated. As a result the cost is reduced for the structure and for the warhead.